Utter rudeness from branch manager

The manager of Shoprite Charlesville, Brandon was screaming and throwing a fit when customer came in store to buy stationery in large quantities. He could be heard by people in neighbouring stores and the whole store came to a standstill as he orders the cashier to cancel the entire sale. I asked him to show me where it says quantities are reserved and if so, why cancel the ENTIRE sale. He was so rude and obnoxious because of his supposed little title and shouted at me for calling him to order. What kind of managers are you guys hiring that have utter disrespect for humanity and insult people’s intelligence when it comes to their consumer rights?